1. Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba City, Chiba, Japan,
2. Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, Chiba City, Chiba, Japan
3. Funabashi Orthopaedic Hospital, Funabashi City, Chiba, Japan
4. Department of Orthopaedic Surgery, Matsudo City Hospital, Matsudo City, Chiba, Japan